This invention relates to laminated plastic molded bodies such as cylindrical bodies constituting trunk portions of bottle shaped plastic containers or tube containers.
Various kinds of plastic containers have been on the market as a container for, for example, foods, drinks, cosmetics, chemicals or the like, since they have a light weight, a lower danger of breakage, a low cost and the like. For example, plastic containers made of polyolefin resins such as polypropylene, etc. have been used as containers for general purpose having barrier properties against humidity. Also, plastic containers made of poly(ethylene terephthalate) resins have excellent transparency and oxygen barrier properties, and have been used as containers for various kinds of beverages having beautiful appearance similar to glass bottles.
Moreover, as transparent containers having barrier properties to humidity, stretch blow molded containers using polyolefin resin containing a cyclic olefin component have been proposed (JP-A-7-80919).
However, plastic containers using polyolefin resins such as polypropylene and the like as mentioned above are insufficient in transparency. Also, plastic containers using poly(ethylene terephthalate) resin are insufficient in barrier properties against humidity.
Moreover, the above-mentioned stretch blow molded containers using polyolefin resin containing a cyclic olefin component are poor in stress characteristics, and poor in resistance against vegetable type or mineral type oils or greases. Particularly when residual stress remained in the containers themselves, adhesion of oils at fingers, etc. to the containers may cause crazing or cracking. Also, since a cost of the polyolefin resin containing a cyclic olefin component, which is a starting material for molding, is about ten times that of the poly(ethylene terephthalate) resin, the resin can not be used to make general purpose plastic molded bodies from the viewpoint of its cost.
Thus, a transparent container which is a container for containing, for example, chemicals or cosmetics, etc., which contains a component a function of which is lowered by hygroscopicity, and has excellent characteristics including resistance to vegetable type or mineral type oils or greases cannot be prepared by using the above-mentioned polyolefin type resin such as polypropylene, etc. or the polyethylene terephthalate resin, or a polyolefin resin having a cyclic olefin component.
Accordingly, an object of the present invention is to provide a laminated plastic molded body for general purpose, which is suitable for making a container for containing chemicals or cosmetics, etc., particularly containing a component an action of which is decreased by absorbing humidity, i.e., which is a laminated plastic molded body having an extremely high degree of barrier properties against humidity and excellent transparency and oxygen barrier properties, and also having excellent properties in resistance to vegetable type or mineral type oils or greases.
The above-mentioned problems can be solved by the laminated plastic molded body of the present invention comprising the constitution as mentioned below.
That is, the present invention relates to a three-layered or five-layered multi-layer laminated plastic molded body in which a resin layer A and a resin layer B are laminated alternately, and the resin layer A is a poly(ethylene terephthalate) resin layer, and the resin layer B interposed between said resin layers A is a polyolefin resin layer having a cyclic olefin component.
Also, in the three-layered or five-layered multi-layer laminated plastic body in which a resin layer A and a resin layer B are alternately laminated of the present invention having the above-mentioned constitution, it is preferred that the total weight of the poly(ethylene terephthalate) resin constituting the resin layer A is 95 to 55% by weight and the total weight of the polyolefin resin layer having the cyclic olefin component constituting the resin layer B is 5 to 45% by weight.
In the laminated plastic molded body of the present invention, by making the total weight of the poly(ethylene terephthalate) resin layer constituting the resin layer A 95 to 55% by weight, and the total weight of the polyolefin resin layer having the cyclic olefin component constituting the resin layer B 5 to 45% by weight, a laminated plastic molded body in which a cost of the raw resins for molding does not become so expensive, and degrees of lowering in transparency or oxygen barrier properties are a little as compared with the plastic made of a poly(ethylene terephthalate) resin, and it has an extremely high barrier properties against humidity can be prepared.
The laminated plastic molded body of the present invention according to the above constitution is preferably a plastic container comprising a hollow biaxially drawn blow molded body, or a plastic container comprising a hollow blow molded body.
Also, the laminated plastic molded body of the present invention having the above-mentioned constitution is preferably a cylindrical body constituting a trunk portion of a tube container.
As the poly(ethylene terephthalate) resin to be used for forming the resin layer A constituting inside and outside surface layers of the laminated plastic molded body of the present invention, preferably used is a polyester resin in which 80 mol % or more, preferably 90 mol % or more of the dicarboxylic acid component constituting the polymer is terephthalic acid, and 80 mol % or more, preferably 90 mol % or more of the dialcohol component is ethylene glycol unit.
The polyolefin resin having a cyclic olefin component to be used for formation of the resin layer B interposed between the resin layers A is, for example, an addition polymer of a cyclic olefin and an xcex1-olefin, or a hydrogenated product of a ring-opened polymer of the cyclic olefin (for example, available from Nippon Zeon Co., Ltd.: Zeonex (registered trademark), available from JSR: Arton (registered trademark)), etc. As an addition polymer of the cyclic olefin and the xcex1-olefin, a polymer containing the cyclic olefin component with a ratio of 5 to 60 mol % or so is suitable.
As the cyclic olefin, there may be preferably mentioned, for example, norbornene; bicyclo[2.2.1]hept-2-ene), ethylidenenorbornene; ethylidenebicyclo[2.2.1]hept-2-ene, 6-methylbicyclo[2.2.1]hept-2-ene, 5,6-dimethylbicyclo[2.2.1]hept-2-ene, 1-methylbicyclo[2.2.1]hept-2-ene, 6-ethylbicyclo[2.2.1]hept-2-ene, 6-butylbicyclo[2.2.1]hept-2-ene, 6-isobutylbicyclo[2.2.1]hept-2-ene, 7-methylbicyclo[2.2.1]hept-2-ene, tetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-ethyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-propyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-hexyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-stearyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8,9-dimethyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-methyl-9-ethyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-chlorotetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-bromotetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-fluorotetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8,9-dichlorotetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-cyclohexyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-isobutyltetracyclo[4.4.0.12,5.17,10]-3dodecene, 8-butyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-ethylidenetetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-ethylidene-9-methyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-ethylidene-9-ethyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-ethylidene-9-isopropyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-ethylidene-9-butyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-n-propylidenetetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-n-propylidene-9-methyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-n-propylidene-9-ethyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-n-propylidene-9-isopropyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-n-propylidene-9-butyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-isopropylidenetetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-isopropylidene-9-methyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-isopropylidene-9-ethyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-isopropylidene-9-isopropyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-isopropylidene-9-butyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 5,10-dimethyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 2,10-dimethyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 11,12-dimethyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 2,7,9-trimethyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 9-ethyl-2,7-dimethyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 9-isobutyl-2,7-dimethyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 9,11,12-trimethyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 9-ethyl-11,12-dimethyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 9-isobutyl-11,12-dimethyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, 5,8,9,10-tetramethyltetracyclo[4.4.0.12,5.17,10]-3-dodecene, hexacyclo[6.6.1.13,6.110,13.02,7.09,14]-4-heptadecene, 12-methylhexacyclo[6.6.1.13,6.110,13.02,7.09,14]-4-heptadecene, 12-ethylhexacyclo[6.6.1.13,6.110,13.02,7.09,14]-4-heptadecene, 12-isobutylhexacyclo[6.6.1.13,6.110,13.02,7.09,14]-4-heptadecene, 1,6,10-trimethyl-12-isobutylhexacyclo[6.6.1.13,6.110,13.02,7.09,14]-4-heptadecene, octacyclo[8.8.0.12,9.14,7.111,18.113,16.03,8.012,17]-5-docosene, 15-methyloctacyclo[8.8.0.12,9.14,7.111,18.113,16.03,8.012,17]-5-docosene, 15-ethyloctacyclo[8.8.0.12,9.14,7.111,18.113,16.03,8.012,17]-5-docosene, pentacyclo[6.6.1.13,6.02,7.09,14]-4-hexadecene, 1,3-dimethylpentacyclo[6.6.1.13,6.02,7.09,14]-4-hexadecene, 1,6-dimethylpentacyclo[6.6.1.13,6.02,7.09,14]-4-hexadecene, 15,16-dimethylpentacyclo[6.6.1.13,6.02,7.09,14]-4-hexadecene, pentacyclo[6.5.1.13,6.02,7.09,13]-4-pentadecene, 1,3-dimethylpentacyclo[6.5.1.13,6.02,7.09,13]-4-4-pentadecene, 1,6-dimethylpentacyclo[6.5.1.13,6.02,7.09,13]-4-pentadecene, 14,15-dimethylpentacyclo[6.5.1.13,6.02,7.09,13]-4-pentadecene, heptacyclo[8.7.0.12,9.14,7.11,17.03,8.012,16]-5-eicosene, heptacyclo[8.8.0.12,9.14,7.11,18.03,8.012,17]-5-heneicosene, tricyclo[4.3.0.12,5]-3-decene, 2-methyltricyclo[4.3.0.12,5]-3-decene, 5-methyltricyclo[4.3.0.12,5]-3-decene, tricyclo[4.4.0.12,5]-3-undecene, 10-methyltricyclo[4.4.0.12,5]-3-undecene, pentacyclo[6.5.1.13,6.02,7.09,13]-4,10-pentadecadiene, pentacyclo[4.7.0.12,5.08,13.19,12]-3-pentadecene, methyl-substituted pentacyclo[4.7.0.12,5.08,13.19,12]-3pentadecene, heptacyclo[7.8.0.13,5.02,7.110,17.011,16.112,15]-4-eicosene, nonacyclo[9.10.1.14,7.03,8.02,10.012,21.113,20.014,19.115,18]-5-pentacosene, trimethyl-substituted nonacyclo[9.10.1.14,7.03,8.02,10.012,21.113,20.014,19.115,18]-5-pentacosene, 5-phenyl-bicyclo[2.2.1]hept-2-ene, 5-methyl-5-phenyl-bicyclo[2.2.1]hept-2-ene, 5-benzyl-bicyclo[2.2.1]hept-2-ene, 5-tolyl-bicyclo[2.2.1]hept-2-ene, 5-ethylphenyl-bicyclo[2.2.1]hept-2-ene, 5-isopropylphenyl-bicyclo[2.2.1]hept-2-ene, 1,4-methano-1,1a,4,4a-tetrahydrofluorene, 1,4-methano-1,4,4a,5,10,10a-hexahydroanthracene, cyclopentadiene-acenaphthylene adduct, 5-[xcex1-naphthyl]-bicyclo[2.2.1]hept-2-ene, 5-(acetoracenyl)-bicyclo[2.2.1]hept-2-ene, etc.
As the xcex1-olefin, preferred are, including ethylene, an xcex1-olefin having 3 to 20 carbon atoms such as propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, etc.
An addition polymer with a polyolefin having a cyclic olefin component is a copolymer containing the above-mentioned cyclic olefin component and the ethylene type component as essential components, but in addition to the above components, an unsaturated monomer component capable of copolymerizing with these may be further copolymerized. As the other unsaturated monomer capable of copolymerizing at this time, there may be mentioned a cyclic diene compound such as dicyclopentadiene, etc.
The laminated plastic molded body of the present invention according to the above-mentioned constitution can be molded by the same molding means as the molding of the conventional laminated plastic molded body of the poly(ethylene terephthalate) resin layer and the other thermoplastic resin layer, i.e., by an injection molding or a coextrusion molding, etc. Also, it may be a secondary molded body which utilizes the primary molded body molded by these molding means.
For example, when a laminated plastic molded body being a hollow container is to be made, a parison previously molded by a direct blow molding, or an injection molding or coextrusion molding, etc. is subjected to a secondary molding such as a blow molding or a biaxially drawn blow molding, etc., thereby molding can be carried out. It is preferred to make a hollow container comprising a laminated plastic molded body by a biaxially drawn blow molding since more preferred mechanical properties could be obtained.
Also, when a cylindrical shaped body which constitutes a tube container body portion is to be prepared, a predetermined laminated plastic sheet obtained by a coextrusion molding is further subjected to molding of the tube container body portion so that it is rounded off into a cylindrical shape.